Poppet valve



Patented Dec. 9, 1930 UNITED STATES WARREN NOBLE, 0F DETROIT, 'MICHIGA'NPOPIPET VALVE No Drawing.

This invention relates to the poppet valves of internal combustionengines in connection with which considerable thought and experiment hasbeen exercised in the past by valve and engine designers with a view toperfecting a valve which would satisfactorily withstand the temperaturesto which the valves and especially the exhaust valves of internalcombustion engines are exposed in use.

Among the means employed or suggested have been exhaust valves withspecial means for cooling the stems such as the flow of heat conductingagent therethrough with a view to disperse heat from the head of thevalve through the stem thereof and on the other hand attempt to meet theproblem with more or less success have involved the use of special heatresisting alloys from the heads of the valves calculated to withstandhigh temperatures in view of the difficulty of getting rid of this heatquickly.

The present invention differs materially from this latter attemptedsolution of the problem in that it provides a valve head of a metalliccomposition or alloy which is characterized by its heat conductingproperties as distinguished from purely heat resisting propertieswhereby it lends itself to rapid dissipation of its heat radially fromthe valve head to the seat of the valve and also through the stemthereof if heat dissipation in this direction he also desirable.

More particularly the said invention contemplates of the use of silver,a metal having a very high co-efficient of heat, said silver beingalloyed with a suitable metal or metals to give it the required strengthand wearing properties required in the head of a poppet valve adapted touse in an internal combustion engine. In carrying. the invention toeffect I prefer to use a composition including magnesium 10 per cent andsilver 90 per cent which may have a tensile strength in excess of 63,000pounds and a Brinell hardness ranging above 105. I may use as an alloyfor a poppet valve head a composition including for example aluminum 15per cent and silver 85 per cent, such a composition having a tensilestrength ranging above 40,000 pounds and Brinell hardness rangingApplication filed. September 15, 1.927;, SeriaI NoJ 219,814;

above 140. Both of these comp ositions'are homogeneous and lendthemselves well to finishing by grinding and lappingiof seating surfacesfree from pits and open structure.

' Silver has very high co-eflicient'of heat conductance, and alloyingwith aluminum or magnesium within reasonable limits does not reduce theconductivity to such an extent that its advantage is lost, so that thehigh heat conductivity ofvalve headsmade from such composition is' atypical characteristic.

' Poppet valves depend mainly .for their heat dissipation on thetransfer of heat therefrom' to the valve seats and incidentally throughthe valve seats to metal or cylinder heads but it is obvious that thisdissipation is facilitated by the use ofa metal or alloy in theheadiwhich has this special characteristic and that therefore as aresultof the heat dissipation so promoted, the general temperature ofthe valve head is lower than would otherwise be the'case and. that heatresisting nature of the headi's asra consequence a matter of lessimportance.

Although the use of such a composition is described simply in connectionwith the head of a valve it may be also partly or entirely extended tothe stem of the valve if so desired where conditions of theenginedesigned are such that some of the heat may be dissipated throughthe stem.

A valve in which a silver alloy as suggested is used for the purposes ofobtaining high heat conductivity in the head thereof may be veryadvantageously used with the heat conductive valve seat described in mycopending application Serial No. 219,813, filed Sept. 15, 1927 anarrangement which still further increases the facility with which heatmay pass from the valve to the metal of the cylinder head of the engine.

What I calim is 1-. In a poppet valve for internal combustion engines, ahead composed of a binary alloy of silver and a metallic hardening agentwherein the silver predominates to an extent wherein its inherentco-efl'icient of heat conductivity is characteristic of the alloy, andwherein the hardening agent imparts wear resisting properties to thehead.

2. In a poppet valve for internal combus tion engines, a head composedof a magnesium silver alloy in which the silver predominates to anextent wherein its inherent co-eflicient of heat conductivity ischaracteristic of the alloy, and wherein the magnesium supplies to thealloy great wear resisting 1 properties.

3. In a poppet valve for internal combustion engines, a head composed ofa magnesium silver alloy wherein the approximate proportions of theelements are 10 per cent magnesium and 90 per cent silver.

4. A poppet valve for internal combustion engines, composed of a binaryalloy of silver and a metallic hardening agent wherein the silverpredominates to an extent wherein its inherent co-eflicient of heatconductivity is characteristic of the alloy, and wherein said hardeningagent imparts wear resisting qualities to the head and stem of saidvalve.

5. A poppetvalve for internal combustion engines, composed; of amagnesium silver alloy in which the silver predominates to an extentwherein its inherent co-efiicient of heat conductivity is characteristicof the alloy, and wherein the magnesium imparts wear resistingproperties thereto.

6. A poppet valve for internal combustion engines, composed of amagnesium silver alloy wherein the approximate proportions of theelements are 10 per cent magnesium and 90 per cent silver, and with asuflicient quantity of magnesium included therein to impart wearresisting properties to said valves.

In testimony whereof I aflix my signature.

WARREN NOBLE.

